In recent years, there has been a growing interest in electrical installations on the seabed in depths from a few tens of meters to even kilometers. In bringing power electronics subsea, two general concepts exist: (1) the equipment stays at atmospheric pressure; and (2) the equipment is pressurized to the hydrostatic pressure level on sea ground. The two concepts can be differentiated as follows. Concept (1) has the advantage that standard electric/electronic components, known from onshore installations, can be used, while disadvantages include thick walls needed for the enclosure to withstand the pressure difference between inside and outside. Thick walls make the equipment heavy and costly and prevent efficient cooling of the internal electric and electronic devices and set high requirements on seals and penetrators. Concept (2) has the advantage that no thick walls are needed for the enclosure since no or only a relatively small pressure difference exists between inside and outside the containment.
EP2487327 A1 discloses a subsea electronic system in which an enclosure contains a dielectric liquid and a heat generating component. In operation, heat is transferred from the heat generating electronic component to the water surrounding the enclosure via the dielectric liquid.